New vat dyestuffs of the dipyrazolanthrone series and process of making same



patented May 12, 1951 UNI TED STATES;

PATENT OFFICE RUDOLF' HEIL, 0F OFFENBACH-ON-TI-IE-MAIN, GERMANY, ASSIGNOR TO GENERAL-1 AN'ILINE WORKS, INC., OF NEW YORK, N. Y., A CORPORATION OF'DELAWARE NEW VAT DYESTUFFS OF THE DIPYRAZOIJANTHRONESERIES'AND PROCESS OF'MAKIN'G SAME in. Drawing. Application filed October 5, 1927, Serial No. 224,283, and in Germany October 9,. 1926.

My invention relates to new vat dyestuffs of thedipyrazolanthrone (pyrazole-anthrone-yellow) series, which are obtained by heating to temperatures greater than and not above 200" acompound of the dipy: razolanthrone series corresponding probably to the general formula:

described in German Patent No. 255641,

among its substitution products for instance the. halogenated derivatives are named in; U. S. A..Patent.No. 1595549. Aldehydes of the aliphatic as wellas of the aromatic series are suitable for my process. Under the term acid chlorides as condensing agent I include in the following claims chlorides of phosphorus, antimony and. aluminium. The course of the reaction cannotnow be stated with certainty, but it may be supposed that the aldehyde reacts with one of the groups signified in the aforesaid formula by N -R or N -R The" new dyestuffs obtained according to my process are when dry yellowish colored mostly crystalline powders, soluble in concentrated sulfuric acid with a bluish red color. They dye cotton from a bluish to greenish hydrosulfite vat yellow to orange shades, particularly fast to alkali.

In order to further illustrate my invention' the following examples are given, the

parts being by weight and all temperatures I in centigrade degrees; but I wish it to=be understood, that my invention is not limited to the particular products or reacting conditions mentioned therein.

Example 1 1 part of powdered dipyrazolanthrone is finely suspended in 10 parts of benzaldehyde and while stirring 1 part of phosphorus trichloride is added at about 90 The mass is heated for some time at and after cooling down the raw prod uct of reaction is separated from the excess of benzaldehyde by filtration or' steam distillation. When recrystallized from diluents of a higher boilingv point such as nitrobenzene or trichlorobenzene the dye stuff is obtained in a pure state. It crystallizes in fine scales of a golden lustre. It may be finely divided by mixing it with water and dyes cotton from a bluish green hydrosulfite vat blue shades turning to a pure: yellow, when exposed to the air.

E ma'mple 1 part of dipyrazolanthrone is finely'suspended in 9 parts of trichlorobenzene and 1 part of benzaldehyde and 11, 5 parts of phosphorus trichloride' or 1 part of phosphorus pentachloride or 1 part of aluminium chloride are added. While well stirring the mass is slowly heated to 14 0 and kept for some hours 'at this temperature; The reaction product may be isolated as ,de scribed in the foregoing example; The dyestuif thus obtained is identical with the dyestufi' of Example 1. l

E xample 3 1 part of: powdered dipyrazolanthrone" is suspended-"in 10 parts of nitrobenzene' and after addition of 1 part of metaor 0'rtho'-- "tion from dichlorobenzene.

chlorobenzaldehyde and 1 part of phosphorus trichloride the mixture is heated for some hours to 130-140 while stirring. The formed dyes-tufis may be isolated as described in Example 1 and may be separated from unchanged dipyrazolanthrone by recrystallizing the raw products from nitrobenzene. Both compounds are yellow dyestufi's.

Example 5 To. a mixture of 1 part of powdered dipyrazolanthrone and 10 parts of nitrobenzene 1 part of meta-nitrobenzaldehyde and 1 part of phosphorus trichloride are added and the mass is heated for some hours at 125-130 while stirring. The product of reaction is isolated in the aforesaid manner. It is when dry an olive yellow powder, soluble in sulfuric acid of 66 B. with a bluish red color.

'When replacing the meta-nitrobenzaldehyde by meta-hydroxybenzaldehyde and working otherwise as described above the reaction product is a dark olive-yellow colored substance. It may be filtered oily "110 while stirring. The dyestuff, isolated and washed with hot spirit. It is insoluble in .nitrobenzene.

E ma-mple 6 "heated for some hours to 130-140 while stirringf After cooling down the reddish brown colored solution the product of reaction separates and is isolated by filtration. It may be purified by recrystalliza- It dyes cotton brownish yellow shades.

Example '7 "'trichloride are added and while stirring the mixture is heated at 100 for some hours. After cooling down the raw product of reaction may be purified by removing adhering nitrobenzene by means of a steam disftillation and recrystallizing the residue from nitrobenzene. tained dyes cotton golden orange shades. It dissolves in concentrated sulfuric acid with a reddish orange color.

E pample 8 To a suspension of 1 part of dipyrazolanthrone in 10 parts of nitrobenzene while stirring 1 part of paraformaldehyde and 1 The dyestufl' thus ob-v part of phosphorus trichloride are added. The mixture is heated for some hours at 100120 and after cooling down the re action product is isolated by filtration and freed from exceeding paraformaldehyde dyeing golden orange shades. It dissolves in concentrated sulfuric acid with a bluish red color.

Example 9 a To a mixture of 1 part of monoethyldi- The dyestuft dissolves L pyrazolanthrone and 10 parts of trichlorobenzene 1 part of paraformaldehyde and 1 part of phosphorus trichloride are added and the mass heated for some hours at as described above, dyes cotton dark golden orange shades. It dissolves in concentrated sulfuric acid with a bluish red color.

I claim:

1. As new compounds vat dyestuffs of the dipyrazol anthrone series containing a benzylidene group being when dry yellow colored mostly crystalline powders, soluble in concentrated sulfuric acid with a bluish red color, dyeing cotton from a bluish to greenish hydrosulfite vat yellow to orange shades, particularly fast to alkali, which compounds are substantially identical with products obtainable by heat-ing at temperaturesgreater than 100 C. and not above. 200 C. a compound of the dipyrazol anthrone series having at least one NIT-group with an aromatic aldehyde of the benzene series in the presence of an acid chloride.

2. As a new compound tne vat dyestuif of the dipyrazolanthrone series, containing' a' benzylidene group being when dry a golden yellow powder, crystallizing from organic solvents of a higher boiling point in fine scales, of a golden lustre, soluble in concentrated sulfric' acid with a bluish red color, dyeing cotton from a bluish green colored hydrosulfite vat blue shades turning to a pure yellow when exposed to the air, which compound is substantially iden tical with a product obtainable by heating to about 100150 dipyrazolanthrone with benzaldehyde in presence of an acid chloride as condensing agent.

In witness whereof I have hereunto signed my name this 23rd day of September RUD OLF HEIL. 

